Freezing/Scalding showers

[Jayhawk]

This is a problem we've dealt with but it's annoying and I want to fix it. We have a 15 year old (we've owned it for a couple of years), somewhat upscale for our area, 3.5 bath home with an issue I've never had before. When one shower is in use, and someone turns on water, flushes a toilet, etc., the water in the shower either goes colder or hotter. Is this a case of the builder using cheap valves, and they need to be replaced to fix the problem? We'll have to open walls to get at them, but I'm perfectly willing to do that if we can make this go away. Thanks for your help.

 

[SlowDrip]

Yes, your house lacks anti-scald valves which are now code. Replacing them will fix your problem.

 

[phishfood]

Is this something that just started happening, or has it been a problem the entire time you have lived there?

 

[Jayhawk]

It has always happened in this home. It just didn't seem like this builder, who is known for building quality homes, would have put these kind of (cheap) valves in the home. But it seems that's what he did. This is the fourth home I've owned over the course of 25 years and have never had this issue.

 

[SlowDrip]

If it has always been an issue then it is defiantly "cheap" valves. 15 years ago many places did not legally require pressure balanced valves, now they are code almost everywhere.


To be fair to the builder (for some reason) most "contractor" series of valves back then did not have pressure balancing built in, and if you are buying dozens of valves you probably don't want to pay more for a fancy picture on the box like you do when buying retail.

 

[sdseaman]

We just purchased a house that was built in 1988 and are experiencing the same scalding / freezing issue when any other water source is used during a shower. The house has the original Moen single handle bath / shower controls. I have one local plumber saying that they are pressure balanced. What was the standard back in 1988? Our last house was built in 1993 and the showers were fine.

I have new faucets but am afraid to install them if it won't correct this issue. Please advise and see the attached pic. From my research, a Posi-Temp and MoenTrol were the two Moen lines of pressure balanced faucets and the faucet shows no reference of this name on it.

 

[johnjh2o]

That is a Moen faucet but it is not anti-scald.

 

[sdseaman]

Johnjh20, That was my thought but my plumber of 10 years swears it's a pressure balanced / anti-scald faucet. I'll just replace it and move on. Thanks for your help.

 

[johnjh2o]

Johnjh20, That was my thought but my plumber of 10 years swears it's a pressure balanced / anti-scald faucet. I'll just replace it and move on. Thanks for your help.

Your plumber of ten years more then likely has never installed a shower valve that is not balance pressure. Balance pressure has been required for more then ten years. I have been doing plumbing for over 50 years and that valve is not a balance pressure valve.

 

[journeyman]

John is right that is a moen shower valve. It is not pressure balanced